ER Actress Maura Tierney to Have Breast Tumor Removed

Maura Tierney may have helped save lives as doctor Abby Lockhart on "ER," but she's finding herself in a life and death battle of her own after being diagnosed with a tumor of the breast.

According to Reuters News Service, on Monday, Tierney said in a statement that the mystery illness that has held up shooting on the family TV series, "Parenthood," was cancerous, and that doctors have told her that it is "very treatable."

"I have discovered a tumor in my breast which requires surgery," she said. "I will not know either my exact diagnosis or course of treatment until that surgery is performed. My doctors have all assured me this is a very treatable condition. I'm very optimistic as to the outcome and want to thank everyone who has sent positive thoughts and support. I look forward to going back to work soon."

The 44-year-old also criticized NBC's decision to release a statement on her behalf Friday, saying that it "has unfortunately caused some confusion and undue alarm."

Prior to the discovery of the disease, Tierney had been very active in the movie industry, having attended the wedding of her "ER" co-star, Parminder Nagra, as well as shooting an episode of an Irish talk show in February.

Her latest film, the Tina Fey-produced "Baby Mama," premiered last year. It grossed over $64 million at the box office.